1972 124 BS SPYDER

[JIMRAWLEY]

I HAVE A 1972 SPYDER WITH A 1608 CC A 28/36 DHSA2 CARB . STARTS RUNS FOR LESS THAN A MINUTE THAN ACT LIKE IT STARVES FOR GAS . PUT IN NEW FUEL PUMP NEW PLUGS NEW CAP ROTOR BUTTON, REBUILT CARBERATOR CANT FIND ANY VACUM LEAKS . ANY HELP ?

THANKS

[18Fiatsandcounting]

Starting in 1970, Fiat spiders had a sealed gas tank system. There's a little plastic valve just in front of the fuel tank that is supposed to admit air to the tank so it doesn't build up a vacuum inside the tank as fuel is being pulled out, and these old valves simply fail over time.

Try loosening the gas cap a turn or two and see if the problem goes away. If it does, it's likely a problem with that valve. If it doesn't help, it's something else.

-Bryan

[Bagneaux]

My 71 did this and the problem was the gas tank was full of rust and would clog the fuel filter. I cleaned the tank with phosphoric acid, shaking the tank continuously. This and a new fuel filter solved the problem. In my subsequent spiders, I just bought a new gas tank when I got it.